Securing a Sub-Sea Well Where Oil/Gas/Water is Flowing

ABSTRACT

A system and method for securing a flowing sub-sea well using a securing apparatus. The securing apparatus has a gripping assembly to secure the securing apparatus to an outlet the sub-sea well. A bladder assembly seals the securing apparatus to the sub-sea well and fluidly connects the sub-sea well to a riser assembly for collection.

FIELD

The present invention relates securing sub-sea wells, and in particular though non-limiting embodiments, to apparatuses and systems for securing a sub-sea well where any combination of oil, gas, and water is flowing out of the well and into surrounding sea water.

BACKGROUND

Oil and gas exploration and development takes place in numerous places throughout the globe and often deposits are discovered buried deep under an ocean floor. These deposits become targets for deepwater drilling. For example, there are approximately 600 deepwater wells in the Gulf of Mexico with depths of 500 feet or more. Drilling and development of sub-sea oil and gas fields requires specialized equipment to perform tasks and withstand pressures and corrosive elements at deep sea depths.

Numerous safety measures are incorporated into deepwater exploration and development to prevent harm to both crew members and the environment. For example, deepwater wells incorporate blowout preventers (BOPs). A BOP is a specialized valve or similar device used to seal, control, and/or monitor wells. A blowout can occur when the drilling fluid density (total pressure exerted by a fluid column) is exceeded and a reservoir begins flowing into a well. Several BOPs, which may be of varying type and function, may be stacked together in blowout preventer system. A BOP or preventer system is intended to prevent a blowout or free flow of reservoir contents out of the well (and into the sea where the well is under sea level).

BOPs do not always function as intended and the failure of a BOP to prevent the flow of reservoir contents can lead to adverse consequences. For example, the Deepwater Horizon oil spill, which began Apr. 20, 2010, lead to an explosion of a rig platform and a discharge of millions of barrels of oil into the Gulf of Mexico. The BOPs could not be triggered to stymy the flow of oil and a sea-floor oil gusher flowed for eighty-seven days until the gusher was capped on Jul. 15, 2000. The delay in securing the sub-sea well for eighty-seven days substantially increased the amount of oil discharged into the sea and thereby increased the costs and environmental consequences of the oil spill. Unfortunately, with the failure of the BOPs during the Deepwater Horizon event, there was no alternative method to timely secure the gushing well.

Accordingly, there is need for new apparatuses, systems, and methods to secure a sub-sea well that is uncontrollably flowing reservoir contents into surroundings.

SUMMARY

In an example embodiment of the present disclosure, a system for securing a sub-sea well is provided, including: a gripping assembly used to secure a riser to a well and to resist fluid pressure emerging from an outlet disposed in fluid communication with the well; and a bladder sealing assembly fixably engaged sealed over said outlet. The combined gripping assembly and ladder sealing assembly system are disposed in fluid communication with an associated riser.

The outlet may be one of an outlet stub, a throat of a blow-out preventer, a throat of a well head, and a throat of a production tree. The gripping assembly may include: a gripping assembly pipe; and a plurality of gripping elements. The plurality of gripping elements may be configured to fold inward toward the gripping assembly pipe as the gripping assembly pipe is pushed into the outlet. The plurality of gripping elements may be configured to be forced outward away from the gripping assembly pipe via at least one of a hydraulic force and a mechanical force. The gripping elements may be configured to press against sides of the outlet when the at least one of the hydraulic force and the mechanical force is applied.

The system may include at least one of chains, wire rope, and clamps. The at least one of chains, wire rope, and clamps may be configured to further secure the gripping assembly to the outlet.

The bladder sealing assembly may include: a sealing element; at least one pressure chamber; and at least one pressure line. The sealing member may be configured to seal around the outlet. The at least one pressure chamber may be configured to provide pressure against the sealing element such that it forces the sealing element against the outlet. The at least one pressure line may provide pressure to the pressure chamber. A pressure of the pressure chamber may be greater than a pressure of the well and greater than a hydrostatic pressure surrounding the well.

The system may include at least one injection port configured to inject fluids into an internal portion of the bladder sealing apparatus. The system may include a riser assembly extending away from the bladder sealing apparatus. The riser assembly may include: at least one riser pipe; and a buoyancy chamber. The riser assembly may include a processing line fluidly connecting the at least one riser pipe to a processing vessel. The buoyancy chamber may be adjustable.

In an example embodiment of the present disclosure, an apparatus for securing a sub-sea well is provided, including: a gripping assembly having a gripping assembly pipe, and a plurality of gripping members; a bladder sealing assembly having a sealing element, at least one pressure chamber, and at least one pressure line; and a riser assembly having at least one riser pipe, and a buoyancy chamber. The plurality of griping members are configured to fold inward toward the gripping assembly pipe as the gripping assembly pipe is pushed into an outlet of the sub-sea well and are further configured to be forced outward away from the gripping assembly pipe via at least one of hydraulic and mechanical force. The sealing element is configured to seal around the outlet. The at least one pressure chamber is configured to provide pressure against the sealing element such that it presses the sealing element against the outlet. The at least one pressure line provides pressure to the pressure chamber. The apparatus may include at least one injection port configured to inject fluids into the bladder sealing assembly. The apparatus may include a processing line fluidly connecting the riser assembly to a processing vessel. The buoyancy chamber may be adjustable.

In an example embodiment of the present disclosure, a method to secure a flowing sub-sea well, including: placing a gripping assembly of a securing apparatus into an outlet of the sub-sea well, said gripping assembly having a plurality of gripping members; forcing the gripping members against sides of the outlet; securing a bladder sealing assembly to the flowing sub-sea well, said bladder sealing assembly having at least one sealing member configured to seal against at least a portion of the outlet; providing pressure against the sealing member to press the sealing member against at least a portion of the outlet; and fluidly connecting the bladder assembly to a riser assembly. The riser assembly may be fluidly connected to a processing vessel.

DESCRIPTION OF DRAWINGS

FIG. 1 is representation of a blowout event, according to an exemplary embodiment of the present invention.

FIG. 2 is representation of a blowout event, according to an exemplary embodiment of the present invention.

FIG. 3 is representation of a blowout event, according to an exemplary embodiment of the present invention.

FIG. 4 is a side view of a securing apparatus, according to an exemplary embodiment of the present invention.

FIG. 5 is a representation of a securing apparatus being installed to secure a blowout event, according to an exemplary embodiment of the present invention.

FIG. 6 is a side view of a securing apparatus having a gripping assembly installed inside an outlet stub, according to an exemplary embodiment of the present invention.

FIG. 7 is a cross-section view of a securing apparatus installed over an outlet stub, according to an exemplary embodiment of the present invention.

FIG. 8 is a representation of a securing apparatus being installed to secure a blowout event, according to an exemplary embodiment of the present invention.

DESCRIPTION

Wells drilled offshore generally use one of more blowout preventers (BOPs) as a main device to secure the well in the event drilling fluid density (total pressure exerted via a fluid column) is exceeded and a reservoir commences to flow into the well. This is commonly referred to as a “blowout.” When the well is not fluidly connected to a processing vessel or other structure for the collection and processing of the reservoir's contents, the reservoir flows into the surroundings, such as sea-water surrounding a sub-sea well head. Although BOPs are intended to prevent the flow of reservoir contents into surrounding sea-water, in the event of a BOP failure or in the absence of a BOP, the flowing sub-sea well must be quickly secured to prevent further loss of the reservoir's contents and potential harm to the environment.

FIGS. 1 to 3 provide representative illustrations of blowouts that can occur requiring quick securing of the flowing sub-sea well. In FIG. 1, a riser above blow out preventer 20 has been cut or broken leaving outlet stub 26. Because BOP 20 failed to stop fluid flow 62 of reservoir 12, oil and/or gas 28 (and potentially water) is flowing directly into water below sea-level 14. Although shown with outlet stub 26 extending above BOP 20, alternatively, the oil and/or gas 28 may be flowing directly from a throat of the BOP 20. The example shown in FIG. 2 again provides a riser assembly 24 from reservoir 12 connecting reservoir 12 to well head 18 near mud line 16. In this assembly, there is no BOP and the oil and/or gas 28 is flowing from reservoir 12 into the surrounding water directly from well head 18. Similar to FIG. 1, the example shown in FIG. 3 provides oil and/or gas 28 flowing into the surrounding sub-sea level water out of outlet stub 26. In this example, outlet stub 26 extends from a failed sub-sea production tree 22. In each of the examples shown in FIGS. 1 to 3, a flow of oil and/or gas is flowing uncontrollably into the surroundings and needs to be secured to minimize loss and contamination of the surrounding body of water.

In example embodiments of the present invention, a system for securing a flowing sub-sea well is provided. Example embodiments of the present invention include a securing apparatus having a gripping assembly, a bladder sealing assembly, and a riser assembly. The gripping assembly may have a plurality of gripping members configured to grip sides of an outlet stub, well-head interior, or throat of a blow-out preventer. In exemplary embodiments, the gripping assembly secures a pipe to a flowing well at the outlet stub, well head, or blow-out preventer. The gripping members may be mechanically or hydraulically forced against sides of the outlet stub, well-head interior, or throat of a blow-out preventer such that a gripping assembly pipe is secured to the well. In example embodiments of the present invention, a bladder sealing assembly includes a sealing member, which may be elastic, configured to secure the bladder sealing assembly to the well. In exemplary embodiments, pressure may be added to a pressure chamber via at least one pressure line forcing the sealing member against the outlet stub or partially into the well head or throat. In exemplary embodiments, a riser assembly may fluidly connect to the bladder assembly and may be further connected to a processing vessel via a processing line. The riser assembly may include a buoyancy chamber, which may be adjustable. In example embodiments of the present invention, a method of securing a flowing sub-sea well is provided, including attaching a securing apparatus to the flowing sub-sea well via a gripping assembly and bladder sealing assembly.

Referring to the exemplary embodiment of the present invention shown in FIG. 4, there is provided a securing apparatus 10 having a gripping assembly 30, a bladder assembly 36, and a riser 54. Gripping assembly 30 has gripping assembly pipe 32 extending from a bottom portion of bladder assembly 36 and having a plurality of gripping members 34. Gripping assembly pipe 32 has an external diameter less than an internal diameter of an outlet stub, well head interior, or throat of a bladder assembly into which the gripping assembly may be installed. Gripping members 34 are configured to fold against gripping assembly pipe 32 as the gripping assembly is pushed into the outlet stub, well head interior, or throat of a bladder assembly such that the gripping assembly may pass relatively easily into said location. Gripping members 34 are further configured such that gripping members 34 may be forced outward away from gripping assembly pipe 32 upon the application of a mechanical and/or hydraulic force.

Bladder sealing assembly 36 may have an outlet stub receiving section 38 configured to receive a top portion of an outlet stub. Bladder sealing assembly 36 may include one or more injection ports 40 which may be used to inject fluids, e.g. to inhibit the formation of hydrates which could plug the bladder sealing assembly. In FIG. 4, ports 40, outlet stub receiving section 38 and interior cavity 37 are shown as dotted lines as they are inside bladder sealing assembly 36. Bladder sealing assembly 36 fluidly connects riser 54 to gripping assembly pipe 32 such that a flow of reservoir contents into gripping assembly pipe 32 may flow up riser 54 to a processing line. See FIG. 8.

The exemplary embodiment of the present invention shown in FIG. 5 demonstrates the installation of securing apparatus 10 to a flowing sub-sea well having outlet stub 26 extending from one of two BOPs 20. Alternatively, securing apparatus 10 may be installed directly to well head 18 if no BOP 20 is present or to a sub-sea production tree. Gripping assembly 30 is pushed into outlet stub 26 until most or all of gripping assembly pipe 32 is inside outlet stub 26. During installation, flow 62 of from reservoir 12 remains un-impeded. Once gripping assembly 30 is substantially pushed into outlet stub 26, a force may be applied to gripping members 34 such that gripping members push against an interior surface of outlet stub 26. See, e.g., FIG. 6. FIG. 6 provides a representation of a securing apparatus 10 installed into outlet stub 26 showing the interior of outlet stub 26 and BOP 20 such that gripping assembly pipe 32 and gripping members 34 may be seen via dotted lines. As shown, gripping members 34 are forced against an interior surface of outlet stub 26 and/or BOP 20 such that securing apparatus 10 resists an upward force from flowing fluids 62 from reservoir 12 (not shown), fixing securing apparatus 10 to the flowing sub-sea well. Gripping members 34 may be forced outward via mechanical and/or hydraulic forces. In addition to gripping members 34, securing apparatus 10 may be further secured to the flowing sub-sea well using additional securing devices such as chains, wires, and clamps. The additional securing devices may be secured to the BOP, suction anchors, or any other type of anchor fixed to sea floor 16.

FIG. 7 provides a cross-section view of a securing apparatus installed in outlet stub 26 above BOP 20. Gripping members 34 are forced against an interior surface of BOP 20 and outlet stub 26 such that securing member 10 resists movement against a force of flow 62 from reservoir 12 (not shown). Once the gripping assembly 30 is secured, bladder sealing assembly 36 may be lowered over outlet stub 26 (or onto a top portion of BOP 20). Inside bladder sealing assembly 36, sealing member 64 is configured to secure bladder sealing assembly 36 over outlet stub 26. Sealing member 64 may be activated by forcing fluids into pressure chamber 46 via one or more pressure lines 48. A pressure inside pressure chamber 46 is sufficient to force sealing element 64 against and seal around outlet stub 26. The pressure inside chamber 46 is equal to or greater than a pressure from fluid flow 62 and hydrostatic pressure 44. The pressure inside pressure chamber 46 may be increased to resist well shut-in pressure, as necessary.

Injection ports 40 may be incorporated into bladder sealing assembly 36. Injection ports 40 may be used to inject fluids to prevent formation of hydrates. Injection ports 40 may include valves 50, which may be connected to an injection pump or similar device.

Although shown in FIG. 7 as sealing around outlet stub 26, securing apparatus 10 may be secured to a flowing sub-sea well via inserting gripping assembly 30 into a throat of a BOP, well head assembly, or production tree where there is no outlet or outlet stub to seal around. In such instances, elastic member 64 may be energized, forcing sealing member 64 against an inner portion of the BOP, well head, or production tree, and sealing flow up through the bladder sealing assembly 36 and riser 54.

In FIG. 8, an exemplary embodiment of the present invention is provided having a riser assembly 52. As shown, securing apparatus 10 is being installed via pushing gripping assembly 30 into outlet stub 26. Extending from bladder sealing assembly 36 is riser 54 which is part of a riser assembly connecting to buoyancy chamber 56, which may or may not be adjustable. Riser assembly 52 may include valve 58 which may be used to shut down the flow of fluids through riser assembly 52. Riser assembly 52 may include a diverter valve and a processing line 60, which may be connected to a processing/storage vessel.

When installing securing apparatus 10, riser assembly 52 may be moved into position by a vessel or other unit until it is over the flowing sub-sea well. Buoyancy of buoyancy chamber 56 may be adjusted to accommodate connection and sealing. If buoyancy chamber 56 is not adjustable, buoyancy may be pre-set to accommodate engagement of gripping assembly 30 and activation of bladder sealing assembly 36. Riser assembly 52 is lowered until gripping assembly 30 is positioned inside outlet stub 26 (or body of BOP, well head, or production tree). Once in place, the gripping members may be forced outward and the buoyancy of buoyancy chamber 56 may be adjusted to maintain tension on the riser assembly. Bladder sealing assembly 36 may be activated by increasing pressure inside pressure chamber 46 thereby applying a force to sealing element 64. Once bladder sealing assembly 36 is sealed to the flowing sub-sea well, fluid flow 62 passes up through gripping assembly 30, bladder sealing assembly 36 and into riser assembly 52, where fluid flow 62 may be diverted for collection and/or processing.

Sealing assembly 36 and gripping assembly 30 may be configured to accommodate a shut in pressure for the sub-sea well and the well could be shut in and made ready using conventional techniques. In severe weather situations, the well could be shut in until the severe weather subsides, allowing a processing vessel to be move to an area of safety during the period of severe weather. Apparatuses and systems described herein, if available, could be assembled in days and mobilized to a flowing sub-sea well for immediate re-control, saving substantial money for cleanup, loss to industry, and working wages while substantially reducing environmental harm.

While the embodiments are described with reference to various implementations and exploitations, it will be understood that these embodiments are illustrative and that the scope of the inventions is not limited to them. Many variations, modifications, additions, and improvements are possible. Further still, any steps described herein may be carried out in any desired order, and any desired steps may be added or deleted. 

What is claimed is:
 1. A system for securing a sub-sea well, comprising: a gripping assembly used to secure a riser to a well and to resist fluid pressure emerging from an outlet disposed in fluid communication with the well; and a bladder sealing assembly fixably engaged sealed over said outlet, wherein the combined gripping assembly and ladder sealing assembly system are disposed in fluid communication with an associated riser.
 2. The system of claim 1, wherein the outlet is one of an outlet stub, a throat of a blow-out preventer, a throat of a well head, and a throat of a production tree.
 3. The system of claim 2, wherein the gripping assembly comprises: a gripping assembly pipe; and a plurality of gripping elements.
 4. The system of claim 3, wherein the plurality of gripping elements are configured to fold inward toward the gripping assembly pipe as the gripping assembly pipe is pushed into the outlet.
 5. The system of claim 4, wherein the plurality of gripping elements are configured to be forced outward away from the gripping assembly pipe via at least one of a hydraulic force and a mechanical force.
 6. The system of claim 5, wherein the gripping elements are configured to press against sides of the outlet when the at least one of the hydraulic force and the mechanical force is applied.
 7. The system of claim 3, further comprising at least one of chains, wire rope, and clamps; wherein, the at least one of chains, wire rope, and clamps are configured to further secure the gripping assembly to the outlet.
 8. The system of claim 2, wherein the bladder sealing assembly comprises: a sealing element; at least one pressure chamber; and at least one pressure line; wherein the sealing member is configured to seal around the outlet; wherein the at least one pressure chamber is configured to provide pressure against the sealing element such that it forces the sealing element against the outlet; and wherein the at least one pressure line provides pressure to the pressure chamber.
 9. The system of claim 8, wherein a pressure of the pressure chamber is greater than a pressure of the well and greater than a hydrostatic pressure surrounding the well.
 10. The system of claim 8, further comprising at least one injection port configured to inject fluids into an internal portion of the bladder sealing apparatus.
 11. The system of claim 1, further comprising a riser assembly extending away from the bladder sealing apparatus.
 12. The system of claim 11, wherein the riser assembly comprises: at least one riser pipe; and a buoyancy chamber.
 13. The system of claim 12, wherein the riser assembly further comprises a processing line fluidly connecting the at least one riser pipe to a processing vessel.
 14. The system of claim 12, wherein the buoyancy chamber is adjustable.
 15. An apparatus for securing a sub-sea well, comprising: a gripping assembly, comprising: a gripping assembly pipe; and a plurality of gripping members; a bladder sealing assembly, comprising: a sealing element; at least one pressure chamber; and at least one pressure line; and a riser assembly, comprising: at least one riser pipe; and a buoyancy chamber; wherein the plurality of griping members are configured to fold inward toward the gripping assembly pipe as the gripping assembly pipe is pushed into an outlet of the sub-sea well and are further configured to be forced outward away from the gripping assembly pipe via at least one of hydraulic and mechanical force; wherein the sealing element is configured to seal around the outlet; wherein the at least one pressure chamber is configured to provide pressure against the sealing element such that it presses the sealing element against the outlet; and wherein the at least one pressure line provides pressure to the pressure chamber.
 16. The apparatus of claim 15, further comprising at least one injection port configured to inject fluids into the bladder sealing assembly.
 17. The apparatus of claim 15, further comprising a processing line fluidly connecting the riser assembly to a processing vessel.
 18. The apparatus of claim 15, wherein the buoyancy chamber is adjustable.
 19. A method to secure a flowing sub-sea well, comprising: placing a gripping assembly of a securing apparatus into an outlet of the sub-sea well, said gripping assembly having a plurality of gripping members; forcing the gripping members against sides of the outlet; securing a bladder sealing assembly to the flowing sub-sea well, said bladder sealing assembly having at least one sealing member configured to seal against at least a portion of the outlet; providing pressure against the sealing member to press the sealing member against at least a portion of the outlet; and fluidly connecting the bladder assembly to a riser assembly.
 20. The method of claim 19, wherein the riser assembly is fluidly connected to a processing vessel. 